Potential mRNA Vaccine Poised for Release as Bird Flu Pandemic Threatens

The emergence of COVID-19 highlighted the urgency of rapid vaccine development, taking approximately one year to roll out the first SARS-CoV-2 vaccine. Tragically, this was after millions of deaths and economic turmoil. However, if a bird flu pandemic strikes, we can respond significantly faster, thanks to pre-approved mRNA vaccines that are ready for immediate deployment. Phase III trials are actively being conducted in the UK and US.

“An influenza pandemic is highly likely in the future. It’s crucial we are adequately prepared,” states Richard Pebody from the UK Health and Safety Executive.

The primary threat is the H5N1 avian influenza strain, notably clade 2.3.4.4b. Emerging roughly a decade ago, this strain has sprawled among wild bird populations globally, even reaching Antarctica. It has also been reported in numerous wild mammals and poultry farms. Alarmingly, the infection is widespread among dairy cows in the United States.

Since 2024, over 100 cases of human infection have been documented; however, there is no evidence of person-to-person transmission. The risk continues as long as H5N1 avian influenza remains active.

“While we cannot predict the timing or severity of the next pandemic, proactive preparedness is essential as influenza viruses continue to circulate in animal populations and may adapt,” warns Hiwot Hirui from Moderna.

Moderna’s mRNA-1018 vaccine targeting H5N1 has completed Phase I and II trials with no safety concerns reported. Current Phase III trials involve 3,000 volunteers in the UK and 1,000 in the US.

Typically, vaccine trials assess effectiveness; however, due to the limited prevalence of H5N1 in humans, the focus will be on measuring immune responses in participants. Early results indicate a robust immune response, as noted by Hirui.

The trial prioritizes individuals aged 65 and older, along with poultry workers, who face higher risks of avian influenza exposure.

Some countries are stockpiling traditional vaccines against H5N1; for instance, The UK has secured 5 million doses. However, this conventional vaccine, similar to many seasonal influenza vaccines, is produced using chicken eggs, making it challenging to scale up production or adapt quickly if the virus evolves significantly.

In contrast, mRNA vaccine production can be rapidly scaled and easily modified. This adaptability presents a considerable advantage in pandemic preparedness, as outlined by Pebody.

The trial is Funded by the Coalition for Epidemic Preparedness Innovations (CEPI), which has the support of over 30 countries and various organizations, particularly following the reduction in mRNA vaccine funding by the US government.

Countries like England and the US are exploring the rollout of H5N1 vaccines for livestock, especially poultry. This methodology has been employed in various nations for years, with studies in France showing that vaccinating ducks significantly decreased H5N1 infections on farms.